/**************************************************************************
 *
 * Copyright (c) 2000-2003 Intel Corporation
 * All rights reserved.
 * Copyright (c) 2012 France Telecom All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * - Neither name of Intel Corporation nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 **************************************************************************/

/*!
 * \file
 */

#include "ixmlmembuf.h"

#include "ixml.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>

/*!
 * \brief Increases or decreases buffer capacity so that at least 'new_length'
 * bytes can be stored.
 *
 * On error, m's fields do not change.
 *
 * \return
 * 	\li UPNP_E_SUCCESS
 * 	\li UPNP_E_OUTOF_MEMORY
 */
static int ixml_membuf_set_size(
        /*! [in,out] The memory buffer. */
        ixml_membuf *m,
        /*! [in] The new lenght. */
        size_t new_length)
{
        size_t diff;
        size_t alloc_len;
        char *temp_buf;

        if (new_length >= m->length) {
                /* increase length */
                /* need more mem? */
                if (new_length <= m->capacity) {
                        /* have enough mem; done */
                        return 0;
                }

                diff = new_length - m->length;
                alloc_len = MAXVAL(m->size_inc, diff) + m->capacity;
        } else {
                /* decrease length */
                assert(new_length <= m->length);

                /* if diff is 0..m->size_inc, don't free */
                if ((m->capacity - new_length) <= m->size_inc) {
                        return 0;
                }
                alloc_len = new_length + m->size_inc;
        }

        assert(alloc_len >= new_length);

        temp_buf = realloc(m->buf, alloc_len + (size_t)1);
        if (temp_buf == NULL) {
                /* try smaller size */
                alloc_len = new_length;
                temp_buf = realloc(m->buf, alloc_len + (size_t)1);
                if (temp_buf == NULL) {
                        return IXML_INSUFFICIENT_MEMORY;
                }
        }
        /* save */
        m->buf = temp_buf;
        m->capacity = alloc_len;

        return 0;
}

void ixml_membuf_init(ixml_membuf *m)
{
        assert(m != NULL);

        m->size_inc = MEMBUF_DEF_SIZE_INC;
        m->buf = NULL;
        m->length = (size_t)0;
        m->capacity = (size_t)0;
}

void ixml_membuf_destroy(ixml_membuf *m)
{
        if (m == NULL) {
                return;
        }

        free(m->buf);
        ixml_membuf_init(m);
}

int ixml_membuf_assign(ixml_membuf *m, const void *buf, size_t buf_len)
{
        int return_code;

        assert(m != NULL);

        /* set value to null */
        if (buf == NULL) {
                ixml_membuf_destroy(m);
                return IXML_SUCCESS;
        }
        /* alloc mem */
        return_code = ixml_membuf_set_size(m, buf_len);
        if (return_code != 0) {
                return return_code;
        }

        /* copy */
        memcpy(m->buf, buf, buf_len);

        /* null-terminate */
        m->buf[buf_len] = 0;
        m->length = buf_len;

        return IXML_SUCCESS;
}

int ixml_membuf_assign_str(ixml_membuf *m, const char *c_str)
{
        return ixml_membuf_assign(m, c_str, strlen(c_str));
}

int ixml_membuf_append(
        /*! [in,out] The memory buffer */
        ixml_membuf *m,
        /*! [in] The buffer to append */
        const void *buf)
{
        assert(m != NULL);

        return ixml_membuf_insert(m, buf, (size_t)1, m->length);
}

int ixml_membuf_append_str(
        /*! [in,out] The memory buffer */
        ixml_membuf *m,
        /*! [in] The characters to append (null-terminated) */
        const char *c_str)
{
        return ixml_membuf_insert(m, c_str, strlen(c_str), m->length);
}

int ixml_membuf_insert(
        /*! [in,out] The memory buffer */
        ixml_membuf *m,
        /*! [in] The buffer to insert */
        const void *buf,
        /*! [in] The length of the buffer */
        size_t buf_len,
        /*! [in] Position where to insert the buffer */
        size_t index)
{
        int return_code = 0;

        assert(m != NULL);

        if (index > m->length) {
                return IXML_INDEX_SIZE_ERR;
        }

        if (buf == NULL || buf_len == (size_t)0) {
                return 0;
        }
        /* alloc mem */
        return_code = ixml_membuf_set_size(m, m->length + buf_len);
        if (return_code != 0) {
                return return_code;
        }
        /* insert data */
        /* move data to right of insertion point */
        memmove(m->buf + index + buf_len, m->buf + index, m->length - index);
        memcpy(m->buf + index, buf, buf_len);
        m->length += buf_len;
        /* Null terminate */
        m->buf[m->length] = 0;

        return 0;
}
